Two San Francisco residents became critically ill and were hospitalized after drinking herbal tea that contained Aconite, a lethal poison, according to city health officials.

Health officials said Friday that in separate incidents in February and March, a woman in her 50s and a man in his 30s became “critically” ill within an hour of consuming tea made from leaves supplied by Sun Wing Wo Trading Company, located at 1105 Grant Ave. in Chinatown.

Both the man and woman each developed weakness followed by life-threatening abnormal heart rhythms, and required resuscitation and intensive hospital care after they drank the tea, according to health officials.

Lab tests confirmed the presence of a plant-based toxin, Aconite, in the patients and tea samples they provided.

The Health Department’s environmental health inspectors are removing the products consumed by the two patients from the shelves at Sun Wing Wo Trading Company, and the Health Department is working with the proprietor to trace the source of the contamination to ensure safety for future customers.

“Anyone who has purchased tea from this location should not consume it and should throw it away immediately,” Dr. Tomás Aragón, San Francisco’s health officer, said in a statement. “Aconite poisoning attacks the heart and can be lethal.”

People who have purchased and consumed the tea and experienced no symptoms are safe, but should not consume any more of the tea. Those who consume the tea and experience symptoms should call 911 or go immediately to the nearest hospital.

Symptoms usually begin within a few minutes to a couple hours. and can depend on the amount ingested. Symptoms include sensory abnormalities; numbness or tingling of the face, mouth or limbs; weakness in the limbs; paralysis; cardiovascular abnormalities; dangerously low blood pressure; palpitations; chest pain; slow or fast heart beat; irregular heartbeats that can lead to sudden death; gastrointestinal abnormalities; nausea; vomiting; abdominal pain; and diarrhea.

Health officials said there is no antidote for Aconite poisoning. Aconite is also called monkshood, helmet flower, wolfsbane, “chuanwu,” “caowu,” and “fuzi.” It’s used in Asian herbal medicine to treat pains, bruises and other conditions; its raw roots, leaves and flowers are generally toxic but are used only after adequate processing.